Italy's top court will review American Amanda Knox's conviction Wednesday in the gory murder of a British student, potentially opening the door to a fierce extradition battle in a case that has riveted the world.

The court will examine the verdict that found so-called "Foxy Knoxy" and her ex-boyfriend Raffaele Sollecito guilty of killing Meredith Kercher in the university city of Perugia in 2007, and will either uphold it or send the case back to the appeals court.

Kercher was found in a pool of blood in a student house that she shared with Knox in November 2007, half-naked and with her throat slashed. She had been stabbed 47 times in what prosecutors immediately dubbed a satanic rite.

The pair were originally sentenced to 26 and 25 years in prison for the murder, but were acquitted on appeal in 2011 after four years in jail.

Knox, 27, returned to the United States a free woman, but the couple were found guilty again in a shock about-turn in January last year after judges supported prosecutors' theory that Kercher was killed during a sex game gone wrong.

The Seattle native was handed 28 years in prison, while Sollecito was given 25 and had his passport confiscated.

The Italian, who faces immediate imprisonment if the guilty verdict is upheld, said he would be present in court.

"Not being present at the hearing would be like hiding in a corner of the house during a tsunami. You'd be swept away anyway," he said in a recent interview.

"I have not had a life for eight years," Sollecito, 30, said.

Knox, who was reported last month to be engaged to a childhood friend, will not be present, saying in a recent interview that she would have to be dragged "kicking and screaming".

Public opinion in the US has long felt the case against Knox was flawed and that Italian detectives made mistakes -- such as using dirty gloves to collect evidence -- which mean the case should have been thrown out years ago.

US authorities may try to argue she has been a victim of double jeopardy -- being tried twice for the same crime -- but the extradition treaty acknowledges that there is no limit on the number of times cases can be appealed under the Italian legal system.

The US might say returning Knox to Italy's notoriously overcrowded prisons would be a breach of her human rights, and offer to see her serve time back home. A pregnancy could also make it less likely for the US to hand her over.

Harvard law professor Alan Dershowitz told AFP he believes "she will be extradited if it's (the guilty verdict) upheld."

"The Italian legal system, though I don't love it, is a legitimate legal system and we have a treaty with Italy so I don't see how we would resist," he said.

The appeals court found the pair guilty based on DNA proof that three people were at the murder scene: Knox, Sollecito and a third person, Ivory Coast-born drifter Rudy Guede, who is the only person still in prison for the crime.

Both Sollecito and Knox protest their innocence, arguing that the crime scene was contaminated and any DNA collected was therefore not viable.

But prosecutors say the stab wounds show more than one person was involved, and insist Knox and Sollecito fatally slashed Kercher while Guede held her down after she refused to take part in a drug-fuelled erotic game.

The appeals court also placed a lot of importance on a written confession Knox made under police questioning, in which she said she had been in the house and had heard the murder, but had not taken part.

She later retracted the statement, claiming it had been made under duress. Sollecito's legal team has said if it is used as proof against Knox, it should also be used to clear his name -- because in it Knox said he was not there that night.

While the pair have provided each other with alibis, claiming they smoked marijuana and slept together at another apartment on the night of the crime, Sollecito admitted last year that he could not remember if Knox was present all the time.

Kercher's family, who have waited patiently for a definitive verdict since the trial began in 2009, have said they want Knox to be extradited if her conviction is upheld.

Italy's top court will review American Amanda Knox's conviction Wednesday in the gory murder of a British student, potentially opening the door to a fierce extradition battle in a case that has riveted the world.The court will examine the verdict that found so-called Foxy...